To determine whether obliteration of extrafoveal choroidal neovascular membranes using argon laser photocoagulation is useful in preserving visual acuity in eyes with ocular histoplasmosis or senile macular degeneration. To extend our knowledge of the natural history of extrafoveal neovascular membranes in these disorders. To accumulate data on the natural history of subfoveal neovascular membranes. To extend our knowledge of the natural history of atrophic macular scars in ocular histoplasmosis and macular drusen in senile macular degeneration in the fellow eyes of patients with neovascular membranes in the first eye. The methods will be similar to the Diabetic Retinopathy Study.